Representation of potential energy surfaces by discrete polynomials : proton transfer in malonaldehyde¤
نویسنده
چکیده
A new method for the expansion of potential energy surfaces has been developed exploiting the peculiar properties of Hahn polynomials, a class of orthogonal polynomials of a discrete variable which generalize 3j vector coupling coefficients of angular momentum algebra. The method has been tested for the He nonÈHeiles potential, a typical model for coupled oscillators, and applied to the representation of the potential energy surface of malonaldehyde, a prototype system for intramolecular proton transfer in polyatomic molecules. The representation is obtained by Ðtting the polynomial expansion to a set of points calculated by the density functional theory method on a hyperspherical e†ective three-center coordinate system, in view of perspective quantum dynamical calculations of the proton transfer process.
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